This assumes the “+” is not a trick to see if they are stripping the “+” from the username of the email address; which then is automatically flagged as SPAM. Of

This assumes the “+” is not a trick to see if they are stripping the “+” from the username of the email address; which then is automatically flagged as SPAM. Of course this assumes you’re creating a new email per contact, not just using a feature that was never intended as a anti-spam tool.